Apparatus for feeding and handling thin metal sheets



Jan. 20, 1959 LE MOYNE FARNSWORTH APPARATUS FOR FEEDING AND HANDLINGTHIN METAL SHEETS Filed Aug. 1. 1955 7 Sheets-Sheet 1 INVEN TOR. 9&7 W

BY 7M p f u E.

0 m2 5 m2 v i S Em N o Nm vm be m E Jan- 1 LE MOYNE FARNSWORTH 2,869,756

APPARATUS FOR FEEDING AND HANDLING THIN METAL SHEETS Filed Aug. 1, 1955'7 Sheets-Sheet 2 7 I: 65%? IN7V7ENTOR. F a. Z By W W M 1959 LE MOYNEFARNSWORTH APPARATUS FOR FEEDING AND HANDLING THIN METAL SHEETS 7Sheets-Sheet 3 Filed Aug. 1, 1955 INVENTOR.

1959 LEMOYNE FARNSWORTH 2,869,756

APPARATUS FOR FEEDING AND HANDLING THIN METAL SHEETS I Filed Aug. 1,1955 7 Sheets-Sheet 4 J n- 20, 1 LEMOYNE FARNSWORTH APPARATUS FORFEEDING AND HANDLING THIN METAL SHEETS: Filed Aug. 1, 1955 7 Sheets-Sheet 5 7 8 IN VEN TOR. BY" @744 7 WW Fmln ' 1959 LE MOYNE FARNSWORTH2,369,756

APPARATUS FOR FEEDING AND HANDLING THIN METAL SHEETS Filed Aug. 1, 1955'7 Sheets-Sheet 6 IN V EN TOR.

1959- LE MOYNE FARNSWORTH 2,369,756

APPARATUS FORFEEDING AND HANDLING THIN METAL SHEETS Filed Aug. 1, 1955 7Sheets-Sheet 7 30 (l/PCE g 05 0a 59 m5 of My IVENTOR. I

ATTOR/VEVI United States Patent Ofifice 2,859,756 Patented Jan. 20, 1959APPARATUS FOR FEEDING AND HANDLING THIN METAL SHEETS Le MoyneFarnsworth, Racine, Wis., assignor to Automation Machines and EquipmentCo., Inc, Milwaukee, Wis., a corporation of Wisconsin Application August1, 1955, Serial No. 525,600 9 Claims. (Cl. 221-212) This inventionrelates to improvements in apparatus for feeding and handling thin metalsheets.

In the manufacture of lamination discs for electric motors, it isnecessary to feed the discs to a notching press where notches arepunched in the periphery at accurately indexed locations. The handfeeding of these discs to the press is tedious and time-consuming, andin mechanical feeding devices dilficulties have been encountered becauseof the nature of the thin metal discs which are hard to separate andhandle.

It is a general object of the present invention to provide improvedautomatic apparatus for feeding and handling lamination discs forelectric motors, which apparatus is particularly suitable for feedingdiscs from a vertical stack to a notching press.

A further object of the invention is to provide improved apparatus asabove described wherein mechanism is also provided for automaticallyremoving a notched disc from the press or other work station and fordelivering said notched disc to a discharge station.

A more specific object of the present invention is to provide improvedapparatus for feeding and handling thin metal sheets wherein magneticrepulsion is utilized to separate several of the top sheets of a stack,and wherein novel means is employed for retaining the uppermost of saidseparated sheets in separated condition so that it may be gripped andfed to suitable apparatus such as a punch press.

A further object of the invention is to provide apparatus as abovedescribed wherein there is novel co-action between magnetic separatingand holding means and mechanically actuated gripping fingers.

A still further object of the invention isto provide apparatus as abovedescribed wherein the magnets for separating several of the uppermostsheets of a stack are mounted on an elevator, and wherein novel means isprovided for raising and lowering the elevator and magnets to raise andlower the several separated sheets.

A further object of the invention is to provide apparatus for feedingand handling thin metal sheets wherein there is novel transfer mechanismfor moving a sheet of separated material from the magazine to the punchpress and from the punch press to the discharge station.

With the above and other objects in view, the invention consists of theimproved apparatus for feeding and handling thin metal sheets, and allof its parts and combinations as set forth in the claims, and allequivalents thereof.

In the accompanying drawings, illustrating one complete embodiment ofthe preferred form of the invention, in which the same referencenumerals designate the same parts in all of the views:

Fig. l is a plan view of the apparatus, the punch press being indicatedby dotted lines;

Fig. 2 is a fragmentary elevational view taken as indicated by the line2--2 in Fig. 1, the magnets being shown in lowered position; 1

Fig. 3 is a view similar to Fig. 2 showing the magnets and associatedmechanism in elevated position holding several separated discs;

Fig. 4 is a fragmentary sectional view taken approximately along theline 4-4 of Fig. 2 illustrating the pickup head and associated parts andshowing a metal disc being held by the pickup magnet;

Fig. 5 is a view similar to Fig. 4 showing the metal disc being grippedby the fingers, the pickup head being moved out of engagement with thedisc;

Fig. 6 is a view similar to Fig. 4 showing the gripped disc after it hasbeen tilted upwardly at an angle from the position of Fig. 5;

Fig. 7 is a fragmentary sectional view taken approximately on the line77 of Fig. 2 and showing the roller follower;

Fig. 8 is a sectional view taken on the line 88 of Fig. 2 showing one ofthe sets of gripping fingers;

Fig. 9 is a sectional View taken on the line 99 of Fig. 1;

Fig. 10 is a sectional view taken on the line 10-10 of Fig. 9;

Fig. 11 is a transverse sectional view taken on the line 1111 of Fig. 1,the punch press and associated parts being shown by dot-and-dash lines;

Fig. 12 is a fragmentary sectional view taken along the line 12-42 ofFig. 2;

Fig. 13 is a fragmentary sectional view taken along the line 13-13 ofFig. 12;

Fig. 14 is a fragmentary sectional view taken along the line 1414 ofFig. 1;

Fig. 15 is a wiring diagram showing; the electric controls; and

Fig. 16 is a schematic diagram showing the power cylinders and valves.

Referring more particularly to the drawing, first to Fig. 1, it will benoted that there is a suitable frame 20 having spaced transverse guides21, 22 and 23. These guides have aligned openings for slidably receivingrods 24 and 25. The openings in the guide 21 are designated by thenumeral 26 in Fig. 9 and these openings are provided with bushings 27within which the rods are slidable. The transverse guide 22 has openingswhich are designated by the numeral 28 in Fig. 11 and these openings arefitted with bushings 29 and 29', the bushings 29 having a key way 30 forco-action with a key 31 fitted in the rod 25, whereby the rod 25 islocked against rotation during part of its movement as will behereinafter described.

Referring now to Fig. 11, a cylinder 32 having a fluid pressure operatedram 33 is pivotally connected to the frame as at 34.

The end of the ram 33 (see Fig. 11) is pivotally connected as at 35 withone arm of a bell crank lever 36. The said bell crank is pinned by thepin 37 to the bushing 29, which in turn is connected by the key 31 withthe rod 25, so that if the bell crank is tilted in one direction or theother, the rod 25 is rocked. Depending from the opposite end of the bellcrank lever 36 and suitably supported for rotation in a horizontal planeis a holddown member 38, which in the position of Fig. l1, is adapted tohold a metal disc or work piece 39 between it and a supporting disc 40,the latter being secured to the upper end of a rotatably mounted mandril43. It will be noted from Fig. 11 that when the work 39 is being held asshown in Fig. 11, that its periphery overlaps the die 41 of a punchpress so as to be properly supported for the notching operation to beperformed by the punch 42. Suitable well-known mechanism may be provided(not shown) for rotatably indexing the mandril 43 to cause the disc tobe properly indexed for the punching operations.

After the punching operations have been completed on the disc 39, thebell crank 36 is rocked in a counterclockwise direction to lift thehold-down member 58 out of contact with the work. Simultaneouslygripping L fingers or jaws 44 and 45 grip the work. These jaws are bestillustrated in Fig. 8, which illustrates either set of jaws on themachine. The jaw 45 is mounted for rocking movement relative to theshaft 25, and has an extension 46, which projects toward and over therod 24. A headed pin 47 extends slidably through an opening 48 in thearm 46 and is threaded into the projection 49 of a sleeve 50 surroundingthe rod 24. A coil spring 52 between the projection 49 and the arm 46normally urges the jaw 45 to the position of Fig. 8 into contact ofrocking motion of shaft 25 causes the jaw 44 to close into contact withthe lower face of the work piece. Thereafter another three degrees ofrotation of the shaft 25 in a counter-clockwise direction causes jaw 45to rock against the compression of the coil spring 52 and the thin metalwork piece 39 is gripped between the two jaws and tilted upwardlyslightly in preparation for transfer. It will be noted from Fig. 1 thatthere is one set of fingers or jaws such as those shown in Fig. 8 at thework station, and another set, which are identical, at the pickupstation. Because of the identical nature of the parts, the samereference numerals are used to indicate the detailed parts of each setof fingers. However, in Fig. 1, the numeral 45 is applied to the topgripping jaw at the pickup station, and the numeral 45' to thetop-pickup jaw at the work station.

Referring now to Figs. 4, 5, and 6, these figures illustrate parts atthe pickup station. Pinned to a bushing 53 on the shaft 25 by a pin 54is supporting member 55. Detachably and pivotally connected to themember 55 by a screw 56 is an arm 57 which is curved in plan viewasshown in Fig. 1. The outer end of the arm supports a magnetic head 58,having several permanent magnets 59 therein. A removable pin 60 normallyholds the arm 57 against pivotal movement in a horizontal plane on thebolt 56. If, however, the pin is removed, the arm 57 and the magnetichead 58 may be moved out of the way to facilitate loading of the devicewith a new stack of sheet metal discs. in Fig. 4 the uppermost one 61 ofpreviously separated discs is being held in elevated position by theelectromagnets 59 in the magnetic head. In Fig. the disc 61 has beengripped by the jaws 44 and 45 at the pickup station, and the magnetichead has broken away. In Fig. 6 the jaws are shown in upwardly-tiltedposition preparatory to transferring the disc laterally toward the workstation.

Referring now to Figs. 2 and 3, there is illustratedthe pickup station.Suitably supported on a frame portion 62 are vertical sleeves 63 and 64,within which rods 65 are slidable. The upper ends of the rods have heads66 on which pieces of non-magnetic steel 67, which are L-shaped inelevational view, are suitably supported. The upright portions of theseL-shaped pieces are V- shaped in plan view as shown in Fig. 1, so thatall portions fit relatively close to the periphery of the discs in thestack 68 as shown in Fig. 1. Connected to the rear faces of each uprightV-shaped portion of a member 67 is a permanent magnet 69. Each magnethas one pole connected to one part of the V-shaped upright portion, andits other pole connected to the other part of the V-shaped poles, as isclear from Fig. 1

A spindle 70 (see Figs. 2 and 12) has a tapered pin 71 depending fromits lower end and adapted to make wedging engagement in-a tapered hole72 of a member 73. The member 73 has an enlarged head which seats ;onthe upper end of a bushing 74, the latter projecting upwardly from aframe bar 75 as shown in Fig.

2, the bar having a hole 76 in registration with the lower end of thebushing 74, through which the lower iii end of the tapered pin mayproject as shown in Fig. 12. A lever 77, which is pivoted as at 78 tothe bottom side of the bar 75, can be rocked in a clockwise direction toknock out tapered pin 71 when it is desired to remove the spindle forreloading purposes.

A set screw 79 (see Fig. 12) in the side of the bush ing has its innerend engageable with a circular groove 80 around the member 73 to lockthe member 73 against upward movement while permitting rotationaladjustment when the set screw 79 is loosened. The side of the spindle 70has a keyway 81 which is fitted with a key 82. The lower end of the keydepends from the bottom of the spindle and is engageable in a locatingrecess 8-3 of the member 73 so that the spindle is accurately positionedto vary the position of the recess 83. The set screw 79 may be loosenedand the'mernber 73 rotated by means of a handle 84. 1

A stack of the sheet metal discs 61'may be supported on a collar 70 onthe spindle 70 as shown in Fig. 2, and'when the discs are all used up, anew spindle with discs thereon may be quickly substituted after theentire spindle is removed in the manner heretoforedescribed. The discsmay be all keyed to the spindle 70 by the key 82 so that when they arepicked up by the gripping jaws, they will be held in proper position sothat keyways on the sheet metal discs will register with a key 43' onthe punch press mandrel 43.

Referring to Figs/2 and 3, a cylinder 85 for a fluid pressure operatedram 86 is pivotally connected to the frame 62 at 87. The upper end ofthe ram is pivotally connected at 88 to a' bent lever 89. The inner endof the lever 89 is keyed to a jackshaft 90 as at 90'. Also keyed to thejackshaft 90 by the key 90" is one endof a forked member 91, whichmember ha'sitsbther end forked as at 92 to co-act with a pin 93 on acrossmember 95 of the magnet elevating structure.

The upper end of the member 89 is bent as at 96 and has a pad 97 at itsend whi'chis engageable'with a roller 98 (see Fig. 2). The roller 98 isbest shown in Fig. 7 and is rotatable on a shaft 99, which is mounted ina member 100, the latter moving with-the horizontal rods 24 and 25 fromthe position of Fig. 2 to the position of Fig. 3 when the latter areshifted. I V

Mounted between cross-members 21 and 22 (see Fig. l) is the cylinder 101of a fluid pressure operated ram, the ram being connected to a head 102to which the ends of the rods 24 and 25 are also connected, as at 103and 104. Also carried by the rods 24 and 25 are stop collars 1.05 at oneend and 106 at the oppositeend, each of which has an inwardly facingtapered face. The tapered face of the collar on the rod 24 is engageablewith an operating Summary of operation Referring first to Fig. 11, thisview illustrates the ram 33 in extended position to hold the holddownmember 38 in contact with the work at the work station as the work isbeing punched by the punch 42 inztheusual manner. At this time limitswitch is notactuated, this being an existing switch on the press forpunch 42, which switch controls the continuance of punch operation bykeeping a solenoid 126 on the press energized. It is to be noted thatbefore lowering ofthe hold-down member 38 to the position of Fig. .11,the metal disc, which in the embodiment illustrated is to form alamination for an electric motor, has been moved into position by thegripping jaws 44 and 45', which deliver the disc without change inposition so that its key recess will engage with a key on the member 40.During the punching operation, 'the disc 89 is rotatably indeXedin-anysuitable mannerby rotation of the spindle 43, the upper hold-down memberrotating therewith.

After the punching operation has been completed as signaled by theopening of limit switch 125. This causes solenoid 126 to bede'energized, which in turn breaks the press rarn to stop punch 42.Simultaneously limit switch 125 also closes a contact 127 energizingrelay coil 128. Coil 123 causes closing of contacts 129 which in turnenergizes relay coil 131) through relay contacts 131, the latter havingbeen energized during the above-mentioned punching stroke by contacts132 and held energized by contacts 133. Relay 130 causes closing ofcontact 134, the latter energizing solenoid 135. The cylinder 32 of Fig.11 is preferably operated by pneumatic means under the control of asuitable solenoid-operated valve 136 as is well-known in the art.Solenoid 135 shifts valve 136 (as shown in Fig. 16) so that air pressureis directed to the cylinder 32 in a direction to cause ram 33 to beretracted. During retracting movement of the ram 33, the bell cranklever 36 is rocked in a counter-clockwise direction, lifting thehold-down member 33 out of contact with the disc 39, being worked on. Asthe hold-down member 38 leaves the work piece, the latter is gripped bythe jaws 44 and 45. Referring to Fig. 8, which shows one of the sets ofjaws, they are operated as a result of rocking movement of the shaft rod25. This rocking movement results because the bell crank 36 of Fig. 11is pinned to the bushing 29, and the latter in turn is keyed to theshaft 25. Also, the finger which is attached to the lower jaw 44 ispinned to the shaft 25 so that as the shaft rocks, the jaw 44 movesupwardly to cause gripping of the metal disc between the two jaws.Further rocking movement causes the jaws to tilt the disc upwardly aboutthree degrees against the tension of the coil spring 52 of Fig. 8. Thedisc is now removed from the work sup' port 40 and is ready for lateraltransfer. These movements of the jaws are the same as are illustrated inFigs. 4, 5 and 6. However, Figs. 4, 5 and 6 are taken at the pickupstation, rather than at the work station.

Simultaneous with the above operation, the rocking of the shaft 25causes arm 57 of Fig. 4, at the pickup station, to lift up to theposition of Fig. 5, because the arm 57 is pinned to the bushing 53, andthe latter is keyed to the shaft 25, which is rocking. At the same timethat the magnetichead 58 is being moved upwardly from the position ofFig. 4 to the position of Fig. 5, the fingers 44 and 45 shown in Figs.4, 5 and 6 are moved from the position of Fig. 4 to the position of Fig.5 to grip the sheet metal disc which has previously been held by themagnetic head. Just as the disc is gripped by the jaws 44 and 45 of Fig.5, it is moved slightly upwardly by the magnetic head until it engagesthe jaw 45. The latterholds the disc against the further upward movementwhile the magnetic head 58 breaks itself away, the jaws 44 and 45 ofFig. 5 closing just before breaking away takes place. Thereafter thejaws tilt the disc an additional three degrees to the position of Fig.6. There is now a disc in the position of Fig. 6 at the pickup station,and another disc in the same gripped and tilted position at the workstation. The latter disc is to be moved to a spindle 111 at a dischargestation 112. The disc which has been picked up as shown in Fig. 6 is tobe moved to the work station to be punched. It is held tightly by thejaws 44 and 45 in the exact indexed position as it was keyed on thespindle 70 at the pickup station.

Boring the rocking of bell crank 36 as shown in Fig. ll, a projection113 releases the button 114 of a limit switch 115 to open the lattercontact and close circuit to contact 137. This then energizes solenoids133 and 139. Solenoid 138 shifts valve 140 for starting the flow offiuid under pressure into cylinder 1111 to extend the ram thereof, whichresults in movement of the head 102 toward the right in Fig. 1. Thiscauses sliding movement of the rods 24 and 25. After about 9" of suchmovement, the left hand end of the key 31 runs out of the keyway 116 in6 the bushing 53 of member 23 (see Fig. 14). Thereafter the spring 118of Fig. 5 is able to rock the arm 57 in a clockwise direction from theposition of Fig. 5 to the position of Fig. 4 ready to receive theuppermost of several separated discs 61 as in Fig. 3.

The rods 24 and 25 continue to move toward the right until the finishedwork piece is over the discharge station 112 and the new piece of workis over the work station at 49 ready to be punched.

Solenoid 139 shifts valve 141 for starting flow of fluid under pressureinto cylinder to extend its ram 86 to move the lever 89 from theposition of Fig. 2 to the position of Fig. 3. This causes upwardmovement of the telescoped rod 65 and upward movement of the magnets 69from the position of Fig. 2 to the position of Fig. 3. These magnets acton several of the uppermost discs of the stack to cause said discs to bemagnetized in a like manner, so that they repel one another. Thusseveral of the discs 61 are separated from the top of the stack and arecarried by the magnets up to the fully elevated position of Fig. 3 untilthe uppermost disc 61 contacts the bottom of the magnetic head 58, themagnets in the latter holding the top metal disc to it.

During the extension movement of the ram 86 of cylinder 85, the roller98 controls the rate of elevating movement to prevent any snap action incase of faulty operation of the pneumatic cylinder 85.

When the ram of cylinder 101 has been fully extended, the taperedsurface of collar 106 on the rod 24 engages the operating finger 1119 ofthe limit switch 110. This opens switch 111) (lo-energizing relay coil142 causing contacts 133 and 131 to open. The latter de-energize relaycoil 130, opening relay contact 134. The opening of contact 134de-energizes solenoid 135 allowing valve spring 144 to return the valve136 to its normal position causing fluid under pressure to flow thereinto extend the ram 33 so that the work piece 39, which is gripped by thefingers 44 and 45 is moved down onto the support 40 at the work station.

At the same time that the jaws 44 and 45 lower the work piece 39 to theposition of Fig. 11, the hold-down head 38 rocks down to hold the discin position while it is being notched.

Simultaneously, as a result of rocking of the shaft 25, the other set offingers 44 and 45' are lowering the finished work piece onto the spindle111 at the discharge station. The first three degrees of rockingmovement in a clockwise direction brings the upper jaws down to theposition shown in Fig. 8 until stopped by the head of pin 47. Thereafterfurther rocking movement of the shaft 25 lowers the jaws 44 to releasethe work.

At the completion of said lowering movement, the button 1'14 of limitswitch of Fig. 11 is depressed. This causes the opening of contact 137and the closing of circuit through contact 115. The latter being inseries with contact 103, which was closed upon start of stroke of ram ofcylinder 1611, energizes solenoid 145. Solenoid 145 shifts valve 146 forstarting flow of fiuid under pressure into a conventional cylinder onthe press which initiates the punching action of punch 42. Upon openingof contact 115, soienoids 138 and 139 are de-energized, allowing theirrespective springs 147 and 148 to return valves 140 and 141 to theirnormal positions. This acts to direct fluid under pressure for thecylinder 101 to cause retraction of the head 102 to bring all the partsback to the original position of Fig. 1. After the start of theoperation of punch 42 switch is released, opening contact 127 andclosing contact 125'. The opening of contact 127 de-energizes relay coil128 and energizes solenoid 126 on the press. Upon full retraction ofhead 102, switch is opened, de-energizing solenoid 145.

As soon as the cylinder 1G1 starts the head 162 back towards theposition of Fig. 1, the ram 86 of the cylinder 85 is simultaneouslyretracted to cause lever 89 to return from the position of Fig. 3 to theposition of Fig. 2. Such,

retraction is snubbed by the fluidin the cylinder85. Dur- :ing su'chTowering movement, all'of the separated discs {shown elevated in Fig. 3are returned to the stack, except the uppermost one, as is shown in Fig.2. It is preferred to work the controls out so that the punch 42 isstarted .only when the switch 115 is tripped as in Fig. 11, and whilethe switch 108 of Fig. 10 is not tripped.

As before mentioned, after all of the discs at the pickup station havebeen used up, the lever 77 is depressed to push out the tapered pin 71(see Fig. 12) and permit removal of the spindle 70. It may be quicklyreplaced by a new spindle containing a stack of metal discs. The lever84 is manipulated when the set screw 79 is loosened, only during setupto insure that the member 73 is in a proper position so that the key 82of the spindle 70 is indexed in a proper position to correspond with thekey of the spindle 43 at the work station. Thus proper positioriing ofthe blanks while being punched is assured.

While the device is particularly suited for use in feeding metal discsto a notching press such as is done when manufacturing laminations forelectric motors, nevertheless the apparatus may be used to feed variousother metal sheets to various types of instruments.

Various changes and modifications may be made without departing from thespirit of the invention, and all such changes are contemplated as maycome within the scope of the claims.

What I claim is:

1. In a device for feeding metal sheet material from a stack to a workstation, said device having a support for said stack and having a workstation at one side of said stack support, gripping jaws, meanssupporting said jaws for movement from a position over said stacksupport to a position adjacent said work station, means for cansing suchmovement, a magnetic holding head supported in vertically spacedrelationship above said stack support, means other than said magneticholding head for separating a sheet of metal from said stack, means forelevating the sheet into contact with said magnetic holding head to betemporarily held in elevated position thereby, gripping jaw operatingmeans for causing said gripping jaws to grip said elevated andmagnetically held sheet, means for moving said magnetic head out ofcontact with said gripped sheet, so that it is thereafter held only bythe gripping jaws for movement to a position adjacent the work station,and means for synchronizing the operation in timed relationship with oneanother of said sheet separating means, sheet elevating means, grippingjaw operating means, magnetic head moving means, and moving means forsaid jaw supporting means.

2. In a device for feeding metal sheet material from a stack on aspindle to a work station, said device having a stack supporting spindleand having a work station at one side of said stack spindle, transfermeans having a tiltably mounted gripping jaw assembly movable with saidtransfer means from a position over said stack spindle to a positionadjacent said work station, a magnetic holding head supported invertically spaced relationship above said stack spindle, means otherthan said magnetic holding head for separating a sheet of material fromsaid stack, means for elevating the sheet on the spindle into contactwith said magnetic holding head, gripping jaw operating means forcausing said grpping jaws to grip said elevated sheet, means for movingsaid magnetic head out of contact with said gripped sheet, means fortilting said gripping jaw assembly to remove said gripped sheet from thespindle, means for causing transfer movement of the transfer means, andmeans for synchronizing the operation in timed relationship with oneanother of said sheet separating means, sheet elevating means, grippingjaw operating means, magnetic head moving means, gripping jaw tiltingmeans, and transfer means.

3. In a device for feeding metal sheet material from a stack on aspindle to a work station, said device having ing a sheet of materialfrom said stack,

a stack supporting spindle and having ,a workstation at .one. side ofsaid stack spindle, movably supported 'transfer means having a tiltablymounted, gripping jaw assembly movable with said transfer means from aposition oversaid stack spindle to a position adjacent said workstation, a magnetic holding head tiltably supported in vertically spacedrelationship above said stack spindle, means other than said magneticholding head for separatmeans for elevating the sheet on the spindleinto contact with said magnetic holding head, gripping jaw operatingmeans for causing said gripping jaws to grip said elevated sheet, meansfor tilting said magnetic head out of contact with said sheet while thelatter is held by the gripping jaw assembly, means for thereaftertilting said gripping jaw assembly to remove said gripped sheet from thespindle, means for causing transfer movement of the transfer means, andmeans for synchronizing the operation in timed relationship with oneanother of said sheet separating means, sheet elevating means, grippingjaw operating means, magnetic head tilting means, gripping jaw assemblytilting means, and transfer means.

4. In a device for feeding metal sheet material from a stack to a workstation, said device having a support for said stack and having a workstation at one side of said stack support, gripping jaws, meanssupporting said jaws for movement from a position over said stacksupport to a position adjacent said work station, means for causing saidmovement, a magnetic holding head supported in vertically spacedrelationship above said stack support, magnetic means other than saidmagnetic holding head for separating a sheet of material from saidstack, means for elevating the sheet into contact with said magneticholding head to be temporarily held in elevated position thereby,gripping jaw operating means for operating said gripping jaws to causethem to grip said elevated and magnetically held sheet, means for movingsaid magnetic head out of contact with said gripped sheet so that it isthereafter held only by the gripping jaws for movement to a positionadjacent the work station, and means for synchronizing the operation intimed relationship with one another of said sheet separating means,sheet elevating means, gripping jaw operating means, magnetic headmoving means, and moving means for said jaw supporting means.

5. In a device for feeding metal sheet material from a stack to a workstation, said device having a support for said stack and having a workstation at one side of said stack support, gripping jaws, meanssupporting said jaws for movement from a position over said stack support to a position adjacent said work station, means for causing saidmovement, a magnetic holding head supported in vertically spacedrelationship above said stack support, means for simultaneouslyseparating several of the uppermost sheets from said stack, means forelevating them until the uppermost of separated sheets contacts saidmagnetic holding head to be temporarily held in elevated positionthereby, gripping jaw operating means for causing said gripping jaws togrip said held sheet, means for moving said magnetic 'head out ofcontact with said gripped sheet so that it is thereafter held only bythe gripping jaws for movement to a position adjacent said work station,and means for synchronizing the operation in timed relationship with oneanother of said sheet separating means, sheet elevating means, grippingjaw operating means, magnetic head moving means, and moving means forsaid jaw. supporting means.

6. In a device for feeding and handling metal sheet material, a seriesof stations including a pickup station having means for holding a stackof sheets of said material, a discharge station, and a work stationintermediate said pickup station and discharge station; sets' ofsheet-handling means, said sets being so spaced that one is in positionat the pickup station when the other is in 9 position at the workstation, and one is at the discharge station when the other set is atthe work station; means supporting said sets of sheet-handling means formovement to and from said positions; means for causing such movement ofsaid sets; means for transferring a sheet of material from the top ofsaid stack at the pickup station to one of the sets of sheet-handlingmeans when said set is at the pickup station; and means for operatingsaid sets of sheet handling means in synchronism with one another tohold determined intervals, and means for synchronizing the operation ofsaid transferring means in timed relationship with the operation of saidsets of sheet handling means.

7. In a device for feeding circular metal discs from a stack, saiddevice including a support for a stack of said discs, disc transfermeans having means for moving a disc from a position over said stacksupport, means for separating a disc from said stack, means forelevating the disc to a position where it may be engaged by saidtransfer means, said separating means including a permanent magnetpositioned on opposite sides of the stack adjacent the edges of thediscs and there being a non-magnetic support for each magnet which isV-shaped and positioned to embrace a portion of the circular peripheryof the disc in its V.

8. In a device for feeding metal sheet material from a stack to a workstation, said device having a support for said stack and having a workstation at one side of the stack support, gripping jaws, meanssupporting said gripping jaws for tilting movement and for movement froma position adjacent said stack to a position adjacent said work station,means for tilting said jaws, means for moving said jaws between saidstack and work station, a magnetic holding head movably supported invertically spaced relationship above said stack, an elevator includingmagnetic repulsion means adjacent opposite edges of the sheets in thestack for simultaneously separating and release said sheet at preseveralof the uppermost sheets in the stack and for elevating them until theuppermost one of said sheets contacts said magnetic holding head to-betemporarily held in elevated position thereby, the other elevated sheetsbeing thereafter returned to position on top of the stack, gripping jawoperating means for causing said gripping jaws to grip said held sheet,means for moving said magnetic head out of contact with said sheet Whileit is thus held by the gripping jaws so that it is thereafter held onlyby said gripping jaws preparatory to movement to a position adjacent thework station, and means for synchronizing the operation in timedrelationship with one another of said elevator and magnetic repulsionmeans, gripping jaw operating means, magnetic head moving means, jawtilting means, and jaw moving means.

9. In a device for feeding circular metal discs from a stack, saiddevice including a support for a stack of said discs, disc transfermeans having means for moving a disc from a position over said stacksupport, means for separating a disc from said stack, means forelevating the disc to a position Where it may be engaged by saidtransfer means, said separating means including a permanent magnetpositioned on opposite sides of the stack adjacent the edges of thediscs and there being anonmagnetic support for each magnet which isshaped to embrace a portion of the circular periphery of the disc.

References Cited in the file of this patent UNITED STATES PATENTS1,706,533 Lorig et al Mar. 26, 1929 1,739,101 Strandt Dec. 10, 1 9291,753,449 Swift Apr. 9, 1930 2,533,437 Dennis et al Dec. 12, 19502,728,267 Schaeffer et al. Dec. 27, 1955 FOREIGN PATENTS 500,306 BelgiumJan. 15, 1951

